Prognostic value of K-RAS mutations in patients with non-small cell lung cancer: a systematic review with meta-analysis

Pulmonary enteric adenocarcinoma with progression disease after second - line therapy: a case report

Pulmonary enteric adenocarcinoma (PEAC, also known as Enteric-type adenocarcinoma of the lung, lung - ETAC) is a rare subtype of non-small cell lung cancer (NSCLC) that has the same morphological and immunohistochemical characteristics as colorectal adenocarcinoma and requires gastroenteroscopy to rule out lesions of enteric origin. As a rare solid tumor in lung cancer, PEAC has unique clinical outcome, imaging, pathological and molecular characteristics, and poor prognosis. However, the molecular characteristics and therapeutic biomarkers of PEAC are unclear, and its treatment remains challenging. In this case, we describe a 61-year-old man diagnosed with advanced primary PEAC with KRAS mutation. In the case of unknown PD-L1 expression status, first-line treatment was given to lung adenocarcinoma regimen (immunotherapy combined with chemotherapy), progression occurred after 2 cycles, and progression-free survival (PFS) was 1.5 months. Then the second-line XELOX regimen (oxaliplatin combined with capecitabine) was adjusted. The lesions were significantly reduced after 2 and 4 cycles, and the disease progressed again after 6 cycles, with a PFS of 4.5 months. Anlotinib targeted drugs were selected for third-line treatment, but considering the overall poor condition of the patient, the patient himself refused further treatment. Finally, after discharge, the patient went to the local hospital for nutritional support and symptomatic treatment. The results suggest that standard first-line therapies (immunotherapy plus chemotherapy) and colorectal cancer regimens may have a relatively limited impact on survival in KRAS-driver positive advanced PEAC.

Phase II trial of dual anti-CTLA-4 and anti-PD-1 blockade in rare tumors SWOG/NCI experience: invasive mucinous or non-mucinous lepidic adenocarcinoma of the lung (formerly bronchioloalveolar carcinoma)

Background

Anti-programmed death-1 (PD-1)/cytotoxic T lymphocyte antigen-4 antibodies are efficacious in various malignancies.

Objectives

This study presents the first results of ipilimumab-nivolumab in invasive mucinous or non-mucinous lepidic adenocarcinoma (invasive mucinous adenocarcinoma (IMA) or invasive non-mucinous lepidic adenocarcinomas (INLA), respectively) of the lung.

Design

Dual anti-CTLA-4 and anti-PD-1 blockade in rare tumors (DART) is a prospective, open-label, multicenter (1016 US sites), multi-cohort phase II trial of ipilimumab (1 mg/kg intravenously (IV) every 6 weeks) plus nivolumab (240 mg IV every 2 weeks).

Methods

Participants histologically diagnosed with advanced IMA or INLA, who had not responded to at least one line of therapy, were included in the bronchioloalveolar carcinoma cohort. The primary endpoint was the overall response rate (ORR) by Response Evaluation Criteria in Solid Tumors (confirmed complete and partial responses (CR and PR)). Secondary endpoints were progression-free survival (PFS), overall survival (OS), clinical benefit rate (CBR; stable disease (SD) ⩾ 6 months plus ORR), and toxicity.

Results

Eight evaluable patients (median age: 77 years; the number of prior therapies ranged from 0 to 4; one patient with prior exposure to a PD-1 inhibitor; comprising six IMA and two INLA) were treated. One IMA had a 40% regression (PFS 45.2+ months, PD-L1 0%, KRAS G12C mutated, tumor mutational burden [TMB] 13 mut/Mb). One INLA had 66% regression (PFS 23.8 months, PD-L1 unknown, no actionable mutations, TMB 3 mut/Mb). Overall ORR was 25.0% (2/8) and CBR, 62.5% (5/8); PFS for the patients with SD > 6 months was 43.4+, 11.7+, and 8.3 months. The median PFS was 16 months (5.3-not reached) and the median OS was 32.2 months (14.6-not reached). The toxicity profile was similar to previous reports.

Conclusion

Ipilimumab plus nivolumab in the bronchioloalveolar carcinoma cohort (IMA, INLA) resulted in a durable ORR of 25.0% and CBR of 62.5% (PFS, 8.3 11.7+. 23.8 (PR), 43.4+ and 45.2+ (PR) months). Correlative studies to determine response and resistance markers are ongoing. Expanded prospective studies are warranted.

Trial registration

ClinicalTrials.gov registry: NCT02834013.

The molecular characteristics of non-small cell lung cancer in the Northern Territory's Top End

AIM

Indigenous Australians with lung cancer have poorer survival than non-Indigenous Australians. The reasons for the disparity are not fully understood and this study hypothesized that there may be a difference in the molecular profiles of tumors. The aim of this study, therefore, was to describe and compare the characteristics of non-small cell lung cancer (NSCLC) in the Northern Territory's Top End, between Indigenous and non-Indigenous patients, and describe the molecular profile of tumors in the two groups.

METHODS

A retrospective review was conducted of all adults with a new diagnosis of NSCLC in the Top End from 2017 to 2019. Patient characteristics assessed were Indigenous status, age, sex, smoking status, disease stage, and performance status. Molecular characteristics assessed were epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), v-raf murine sarcoma viral oncogene homolog B (BRAF), ROS proto-oncogene 1 (ROS1), Kirsten rat sarcoma viral oncogene homolog (KRAS), mesenchymal-epithelial transition (MET), human epidermal growth factor receptor 2 (HER2), and programmed death-ligand 1 (PD-L1). Student's t-test and Fisher's Exact Test were used in the statistical analysis.

RESULTS

There were 152 patients diagnosed with NSCLC in the Top End from 2017-2019. Thirty (19.7%) were Indigenous and 122 (80.3%) were non-Indigenous. Indigenous patients compared to non-Indigenous patients were younger at diagnosis (median age 60.7 years versus 67.1 years, p = 0.00036) but were otherwise similar in demographics. PD-L1 expression was similar between Indigenous and non-Indigenous patients (p = 0.91). The only mutations identified among stage IV non-squamous NSCLC patients were EGFR and KRAS but testing rates and overall numbers were too small to draw conclusions about differences in prevalence between Indigenous and non-Indigenous patients.

CONCLUSION

This is the first study to investigate the molecular characteristics of NSCLC in the Top End.

Additional impact of genetic ancestry over race/ethnicity to prevalence of KRAS mutations and allele-specific subtypes in non-small cell lung cancer

The KRAS mutation is the most common oncogenic driver in patients with non-small cell lung cancer (NSCLC). However, a detailed understanding of how self-reported race and/or ethnicity (SIRE), genetically inferred ancestry (GIA), and their interaction affect KRAS mutation is largely unknown. Here, we investigated the associations between SIRE, quantitative GIA, and KRAS mutation and its allele-specific subtypes in a multi-ethnic cohort of 3,918 patients from the Boston Lung Cancer Survival cohort and the Chinese OrigiMed cohort with an independent validation cohort of 1,450 patients with NSCLC. This comprehensive analysis included detailed covariates such as age at diagnosis, sex, clinical stage, cancer histology, and smoking status. We report that SIRE is significantly associated with KRAS mutations, modified by sex, with SIRE-Asian patients showing lower rates of KRAS mutation, transversion substitution, and the allele-specific subtype KRASG12C compared to SIRE-White patients after adjusting for potential confounders. Moreover, GIA was found to correlate with KRAS mutations, where patients with a higher proportion of European ancestry had an increased risk of KRAS mutations, especially more transition substitutions and KRASG12D. Notably, among SIRE-White patients, an increase in European ancestry was linked to a higher likelihood of KRAS mutations, whereas an increase in admixed American ancestry was associated with a reduced likelihood, suggesting that quantitative GIA offers additional information beyond SIRE. The association of SIRE, GIA, and their interplay with KRAS driver mutations in NSCLC highlights the importance of incorporating both into population-based cancer research, aiming to refine clinical decision-making processes and mitigate health disparities.

Cytosolic DNA sensor AIM2 promotes KRAS-driven lung cancer independent of inflammasomes

Constitutively active KRAS mutations are among the major drivers of lung cancer, yet the identity of molecular co-operators of oncogenic KRAS in the lung remains ill-defined. The innate immune cytosolic DNA sensor and pattern recognition receptor (PRR) Absent-in-melanoma 2 (AIM2) is best known for its assembly of multiprotein inflammasome complexes and promoting an inflammatory response. Here, we define a role for AIM2, independent of inflammasomes, in KRAS-addicted lung adenocarcinoma (LAC). In genetically defined and experimentally induced (nicotine-derived nitrosamine ketone; NNK) LAC mouse models harboring the KrasG12D driver mutation, AIM2 was highly upregulated compared with other cytosolic DNA sensors and inflammasome-associated PRRs. Genetic ablation of AIM2 in KrasG12D and NNK-induced LAC mouse models significantly reduced tumor growth, coincident with reduced cellular proliferation in the lung. Bone marrow chimeras suggest a requirement for AIM2 in KrasG12D-driven LAC in both hematopoietic (immune) and non-hematopoietic (epithelial) cellular compartments, which is supported by upregulated AIM2 expression in immune and epithelial cells of mutant KRAS lung tissues. Notably, protection against LAC in AIM2-deficient mice is associated with unaltered protein levels of mature Caspase-1 and IL-1β inflammasome effectors. Moreover, genetic ablation of the key inflammasome adapter, ASC, did not suppress KrasG12D-driven LAC. In support of these in vivo findings, AIM2, but not mature Caspase-1, was upregulated in human LAC patient tumor biopsies. Collectively, our findings reveal that endogenous AIM2 plays a tumor-promoting role, independent of inflammasomes, in mutant KRAS-addicted LAC, and suggest innate immune DNA sensing may provide an avenue to explore new therapeutic strategies in lung cancer.

Assessing the prognostic value of KRAS mutation combined with tumor size in stage I-II non-small cell lung cancer: a retrospective analysis

Background

KRAS mutation status is a well-established independent prognostic factor in advanced non-small cell lung cancer (NSCLC), yet its role in early-stage disease is unclear. Here, we investigate the prognostic value of combining survival data on KRAS mutation status and tumor size in stage I-II NSCLC.

Methods

We studied the combined impact of KRAS mutational status and tumor size on overall survival (OS) in patients with stage I-II NSCLC. We performed a retrospective study including 310 diagnosed patients with early (stage I-II) NSCLCs. All molecularly assessed patients diagnosed with stage I-II NSCLC between 2016-2018 in the Västra Götaland Region of western Sweden were screened in this multi-center retrospective study. The primary study outcome was overall survival.

Results

Out of 310 patients with stage I-II NSCLC, 37% harbored an activating mutation in the KRAS gene. Our study confirmed staging and tumor size as prognostic factors. However, KRAS mutational status was not found to impact OS and there was no difference in the risk of death when combining KRAS mutational status and primary tumor size.

Conclusions

In our patient cohort, KRAS mutations in combination with primary tumor size did not impact prognosis in stage I-II NSCLC.

KiSS-1 Modulation by Epigenetic Agents Improves the Cisplatin Sensitivity of Lung Cancer Cells

Epigenetic alterations my play a role in the aggressive behavior of Non-Small Cell Lung Cancer (NSCLC). Treatment with the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA, vorinostat) has been reported to interfere with the proliferative and invasive potential of NSCLC cells. In addition, the DNA methyltransferase inhibitor azacytidine (AZA, vidaza) can modulate the levels of the metastasis suppressor KiSS-1. Thus, since cisplatin is still clinically available for NSCLC therapy, the aim of this study was to evaluate drug combinations between cisplatin and SAHA as well as AZA using cisplatin-sensitive H460 and -resistant H460/Pt NSCLC cells in relation to KiSS-1 modulation. An analysis of drug interaction according to the Combination-Index values indicated a more marked synergistic effect when the exposure to SAHA or AZA preceded cisplatin treatment with respect to a simultaneous schedule. A modulation of proteins involved in apoptosis (p53, Bax) was found in both sensitive and resistant cells, and compared to the treatment with epigenetic agents alone, the combination of cisplatin and SAHA or AZA increased apoptosis induction. The epigenetic treatments, both as single agents and in combination, increased the release of KiSS-1. Finally, the exposure of cisplatin-sensitive and -resistant cells to the kisspeptin KP10 enhanced cisplatin induced cell death. The efficacy of the combination of SAHA and cisplatin was tested in vivo after subcutaneous inoculum of parental and resistant cells in immunodeficient mice. A significant tumor volume inhibition was found when mice bearing advanced tumors were treated with the combination of SAHA and cisplatin according to the best schedule identified in cellular studies. These results, together with the available literature, support that epigenetic drugs are amenable for the combination treatment of NSCLC, including patients bearing cisplatin-resistant tumors.

Unveiling the role of KRAS in tumor immune microenvironment

Kirsten rats sarcoma viral oncogene (KRAS), the first discovered human oncogene, has long been recognized as "undruggable". KRAS mutations frequently occur in multiple human cancers including non-small cell lung cancer(NSCLC), colorectal cancer(CRC) and pancreatic ductal adenocarcinoma(PDAC), functioning as a "molecule switch" determining the activation of various oncogenic signaling pathways. Except for its intrinsic pro-tumorigenic role, KRAS alteration also exhibits an unique immune signature characterized by elevated PD-L1 level and high tumor mutational burden(TMB). KRAS mutation shape an immune suppressive microenvironment by impeding effective T cells infiltration and recruiting suppressive immune cells including myeloid-derived suppressor cells(MDSCs), regulatory T cells(Tregs), cancer associated fibroblasts(CAFs). In immune checkpoint inhibitor(ICI) era, NSCLC patients with mutated KRAS tend to be more responsive to ICI than patients with intact KRAS. The hallmark for KRAS mutation is the existence of multiple kinds of co-mutations. Different types of co-alterations have distinct tumor microenvironment(TME) signatures and responses to ICI. TP53 co-mutation possess a "hot" TME and achieve higher response to immunotherapy while other loss of function mutation correlated with a "colder" TME and a poor outcome to ICI-based therapy. The groundbreaking discovery of KRAS G12C inhibitors significantly improved outcomes for this KRAS subtype even though efficacy was limited to NSCLC patients. KRAS G12C inhibitors also restore the suppressive TME, creating an opportunity for combinations with ICI. However, an inevitable challenge to KRAS inhibitors is drug resistance. Promising combination strategies such as combination with SHP2 is an approach deserve further exploration because of their immune modulatory effect.

Activation of KrasG12D in Subset of Alveolar Type II Cells Enhances Cellular Plasticity in Lung Adenocarcinoma

We have previously identified alveolar type II cell as the cell-of-origin of KrasG12D-induced lung adenocarcinoma using cell lineage-specific inducible Cre mouse models. Using gain-of-function and loss-of-function genetic models, we discovered that active Notch signaling and low Sox2 levels dictate the ability of type II cells to proliferate and progress into lung adenocarcinoma upon KrasG12D activation. Here, we examine the phenotype of type II cells after Kras activation and find evidence for proliferation of cells that coexpress type I and type II markers. Three-dimensional organoid culture and transplantation studies determine that these dual-positive cells are highly plastic and tumor initiating in vivo. RNA sequencing analysis reveals that these dual-positive cells are enriched in Ras/MAPK, EGFR, and Notch pathways. Furthermore, the proliferation of these cells requires active Notch signaling and is inhibited by genetic/chemical Sox2 upregulation. Our findings could provide new therapeutic strategies to target KRAS-activated lung adenocarcinomas.

SIGNIFICANCE

Identification of progenitor like tumor-initiating cells in KRAS-mutant lung adenocarcinoma may allow development of novel targeted therapeutics.

Invasive Diagnostic Procedures from Bronchoscopy to Surgical Biopsy-Optimization of Non-Small Cell Lung Cancer Samples for Molecular Testing

Background and Objectives: Treatment of advanced lung cancer (LC) has become increasingly personalized over the past decade due to an improved understanding of tumor molecular biology and antitumor immunity. The main task of a pulmonologist oncologist is to establish a tumor diagnosis and, ideally, to confirm the stage of the disease with the least invasive technique possible. Materials and Methods: The paper will summarize published reviews and original papers, as well as published clinical studies and case reports, which studied the role and compared the methods of invasive pulmonology diagnostics to obtain adequate tumor tissue samples for molecular analysis, thereby determining the most effective molecular treatments. Results: Bronchoscopy is often recommended as the initial diagnostic procedure for LC. If the tumor is endoscopically visible, the biopsy sample is susceptible to molecular testing, the same as tumor tissue samples obtained from surgical resection and mediastinoscopy. The use of new sampling methods, such as cryobiopsy for peripheral tumor lesions or cytoblock obtained by ultrasound-guided transbronchial needle aspiration (TBNA), enables obtaining adequate small biopsies and cytological samples for molecular testing, which have until recently been considered unsuitable for this type of analysis. During LC patients' treatment, resistance occurs due to changes in the mutational tumor status or pathohistological tumor type. Therefore, the repeated taking of liquid biopsies for molecular analysis or rebiopsy of tumor tissue for new pathohistological and molecular profiling has recently been mandated. Conclusions: In thoracic oncology, preference should be given to the least invasive diagnostic procedure providing a sample for histology rather than for cytology. However, there is increasing evidence that, when properly processed, cytology samples can be sufficient for both the cancer diagnosis and molecular analyses. A good knowledge of diagnostic procedures is essential for LC diagnosing and treatment in the personalized therapy era.

Prognostic Role of KRAS G12C Mutation in Non-Small Cell Lung Cancer: A Systematic Review and Meta-Analysis

KRAS G12C mutation (mKRAS G12C) is the most frequent KRAS point mutation in non-small cell lung cancer (NSCLC) and has been proven to be a predictive biomarker for direct KRAS G12C inhibitors in advanced solid cancers. We sought to determine the prognostic significance of mKRAS G12C in patients with NSCLC using the meta-analytic approach. A protocol is registered at the International Prospective Register for systematic reviews (CRD42022345868). PubMed, EMBASE, The Cochrane Library, and Clinicaltrials.gov.in were searched for prospective or retrospective studies reporting survival data for tumors with mKRAS G12C compared with either other KRAS mutations or wild-type KRAS (KRAS-WT). The hazard ratios (HRs) for overall survival (OS) or Disease-free survival (DFS) of tumors were pooled according to fixed or random-effects models. Sixteen studies enrolling 10,153 participants were included in the final analysis. mKRAS G12C tumors had poor OS [HR, 1.42; 95% CI, 1.10-1.84, p = 0.007] but similar DFS [HR 2.36, 95% CI 0.64-8.16] compared to KRAS-WT tumors. Compared to other KRAS mutations, mKRAS G12C tumors had poor DFS [HR, 1.49; 95% CI, 1.07-2.09, p < 0.0001] but similar OS [HR, 1.03; 95% CI, 0.84-1.26]. Compared to other KRAS mutations, high PD-L1 expression (>50%) [OR 1.37 95% CI 1.11-1.70, p = 0.004] was associated with mKRAS G12C tumors. mKRAS G12C is a promising prognostic factor for patients with NSCLC, negatively impacting survival. Prevailing significant heterogeneity and selection bias might reduce the validity of these findings. Concomitant high PD-L1 expression in these tumors opens doors for exciting therapeutic potential.

A Review of Biomarkers and Their Clinical Impact in Resected Early-Stage Non-Small-Cell Lung Cancer

The postoperative survival of early-stage non-small-cell lung cancer (NSCLC) patients remains unsatisfactory. In this review, we examined the relevant literature to ascertain the prognostic effect of related indicators on early-stage NSCLC. The prognostic effects of the epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), mesenchymal-epithelial transition (MET), C-ros oncogene 1 (ROS1), or tumour protein p53 (TP53) alterations in resected NSCLC remains debatable. Kirsten rat sarcoma viral oncogene homologue (KRAS) alterations indicate unfavourable outcomes in early-stage NSCLC. Meanwhile, adjuvant or neoadjuvant EGFR-targeted agents can substantially improve prognosis in early-stage NSCLC with EGFR alterations. Based on the summary of current studies, resected NSCLC patients with overexpression of programmed death-ligand 1 (PD-L1) had worsening survival. Conversely, PD-L1 or PD-1 inhibitors can substantially improve patient survival. Considering blood biomarkers, perioperative peripheral venous circulating tumour cells (CTCs) and pulmonary venous CTCs predicted unfavourable prognoses and led to distant metastases. Similarly, patients with detectable perioperative circulating tumour DNA (ctDNA) also had reduced survival. Moreover, patients with perioperatively elevated carcinoembryonic antigen (CEA) in the circulation predicted significantly worse survival outcomes. In the future, we will incorporate mutated genes, immune checkpoints, and blood-based biomarkers by applying artificial intelligence (AI) to construct prognostic models that predict patient survival accurately and guide individualised treatment.

Molecular markers of metastatic disease in KRAS-mutant lung adenocarcinoma

BACKGROUND

Prior studies characterized the association of molecular alterations with treatment-specific outcomes in KRAS-mutant (KRASMUT) lung adenocarcinoma (LUAD). Less is known about the prognostic role of molecular alterations and their associations with metastatic disease.

PATIENTS AND METHODS

We analyzed clinicogenomic data from 1817 patients with KRASMUT LUAD sequenced at the Dana-Farber Cancer Institute (DFCI) and Memorial Sloan Kettering Cancer Center (MSKCC). Patients with metastatic (M1) and nonmetastatic (M0) disease were compared. Transcriptomic data from The Cancer Genome Atlas (TCGA) were investigated to characterize the biology of differential associations with clinical outcomes. Organ-specific metastasis was associated with overall survival (OS).

RESULTS

KEAP1 (DFCI: OR = 2.3, q = 0.04; MSKCC: OR = 2.2, q = 0.00027) and SMARCA4 mutations (DFCI: OR = 2.5, q = 0.06; MSKCC: OR = 2.6, q = 0.0021) were enriched in M1 versus M0 tumors. On integrative modeling, NRF2 activation was the genomic feature most associated with OS. KEAP1 mutations were enriched in M1 versus M0 tumors independent of STK11 status (KEAP1MUT/STK11WT: DFCI OR = 3.0, P = 0.0064; MSKCC OR = 2.0, P = 0.041; KEAP1MUT/STK11MUT: DFCI OR = 2.3, P = 0.0063; MSKCC OR = 2.5, P = 3.6 × 10-05); STK11 mutations without KEAP1 loss were not associated with stage (KEAP1WT/STK11MUT: DFCI OR = 0.97, P = 1.0; MSKCC OR = 1.2, P = 0.33) or outcome. KEAP1/KRAS-mutated tumors with and without STK11 mutations exhibited high functional STK11 loss. The negative effects of KEAP1 were compounded in the presence of bone (HR = 2.3, P = 4.4 × 10-14) and negated in the presence of lymph node metastasis (HR = 1.0, P = 0.91).

CONCLUSIONS

Mutations in KEAP1 and SMARCA4, but not STK11, were associated with metastatic disease and poor OS. Functional STK11 loss, however, may contribute to poor outcomes in KEAP1MUT tumors. Integrating molecular data with clinical and metastatic-site annotations can more accurately risk stratify patients.

Targeting programmed cell death protein 1 (PD-1) for treatment of non-small-cell lung carcinoma (NSCLC); the recent advances

The immune system uses various immune checkpoint axes to adjust responses, support homeostasis, and deter self-reactivity and autoimmunity. Nevertheless, non-small-cell lung carcinoma (NSCLC) can use protective mechanisms to facilitate immune evasion, which leads to potentiated cancer survival and proliferation. In this light, many blocking anti-bodies have been developed to negatively regulate checkpoint molecules, in particular, programmed cell death protein 1 (PD-1) / PD-ligand 1 (L1), and bypass these immune suppressive mechanisms. Meanwhile, anti-PD-1 anti-bodies such as nivolumab, pembrolizumab, cemiplimab, and sintilimab have shown excellent competence in successfully inspiring immune responses versus NSCLC. Accordingly, the United States Food and Drug Administration (FDA) has recently approved nivolumab (alone or in combination with ipilimumab) and pembrolizumab (alone or in combination with chemotherapy) as first-line treatment for advanced NSCLC patients. However, PD-1 blockade monotherapy remains inefficient in more than 60% of NSCLC patients, and many patients don't respond or acquire resistance to this modality. Also, toxicities related to anti-PD-1 anti-body have been progressively identified in clinical trials and oncology practice. Herein, we will outline the clinical benefits of PD-1 blockade therapy alone or in combination with other treatments (e.g., chemotherapy, radiotherapy, anti-angiogenic therapy) in NSCLC patients. Moreover, we will take a glimpse into the recently identified predictive biomarkers to determine patients most likely to suffer serious adverse events to decrease untoward toxicity risk and diminish treatment costs.

Distribution and prognostic impact of EGFR and KRAS mutations according to histological subtype and tumor invasion status in pTis-3N0M0 lung adenocarcinoma

BACKGROUND

The prognostic impact of EGFR mutation as major targetable somatic gene variant on lung adenocarcinoma is controversial. KRAS is another major somatic variant in lung adenocarcinoma, and a therapeutic agent for KRAS G12C became available in clinical settings. These mutations represent clinicopathological features of lung adenocarcinoma and can guide the treatment choice after recurrence. We evaluated the prognostic impact of EGFR and KRAS mutations by considering other clinicopathological recurrence risks in resected pTis-3N0M0 lung adenocarcinoma.

METHODS

Clinicopathological features related to recurrence and genetic status were estimated in consecutive 877 resected cases. Recurrence-free survival (RFS), cumulative recurrence rate (CRR), and overall survival (OS) were compared. Uni- and multivariate analyses for RFS were performed after excluding cases with little or no recurrence risks.

RESULTS

EGFR mutation was more likely to be harbored in female, never-smoker, or patients accompanied by > 5% lepidic component. KRAS mutation was more likely to be harbored in patients with current/ex-smoking history, International Association for the Study of Lung Cancer (IASLC) grade 3, or accompanied lymphatic or vascular invasion. In IASLC grade 2 and 3 patients, EGFR or KRAS mutation cases had significantly worse 5-year RFS than wild type patients (76.9% vs. 85.0%, hazard ratio [HR] = 1.55, 95% confidence interval [CI] = 1.62-6.41, P < 0.001). EGFR or KRAS mutation cases had significantly higher 5-year CRR than wild type patients (17.7% vs. 9.8%, HR = 1.69, 95% CI = 1.44-6.59, P = 0.0038). KRAS mutation cases had higher 5-year CRR than EGFR mutation cases (16.7% vs. 21.4%, HR = 1.62, 95% CI = 0.96-7.19, P = 0.061). There was no significant difference in OS between cohorts. Multivariate analysis revealed that a positive EGFR/KRAS mutation status was risk factor for worse RFS (HR = 2.007, 95% CI = 1.265-3.183, P = 0.003).

CONCLUSION

Positive EGFR and KRAS mutation statuses were risk factors for recurrence in resected IASLC grade 2 and 3 patients. KRAS mutations were more likely to be confirmed in cases with an increased risk of recurrence. EGFR and KRAS mutation statuses should be evaluated simultaneously when assessing the risk of recurrence.

Significant response of pulmonary sarcomatoid carcinoma with obstructive atelectasis to treatment with the PD-1 inhibitor camrelizumab combined with transbronchial cryoablation: A case report and literature review

Pulmonary sarcomatoid carcinoma (PSC) is a rare subtype of non-small cell lung cancer with high malignancy and poor prognosis. Chemotherapy or radiotherapy do not usually provide satisfactory results in patients with PSC, especially in those with advanced-stage cancer. Targeted therapy and immunotherapy are more precise therapies that may be effective in the treatment of PSC; however, further research is needed. Here, we present a case of stage III PSC with obstructive atelectasis, which is more challenging and hinders treatment. Treatment with the PD-1 inhibitor camrelizumab and transbronchial cryoablation showed significant clinical efficacy. This type of combined treatment has not been reported previously for PSC. Thus, this case may provide a valuable reference for future clinical practice and research.

Handling and standardization of EBUS needle aspiration in NSCLC patients: The value of the cell block, a monoinstitutional experience

BACKGROUND

Lung cancer is the main cause of cancer-related death worldwide, and 85% of all lung tumors are non-small cell lung cancers (NSCLC). More than 60% of all lung tumors are diagnosed at an advanced stage, leading to poor prognosis. Given the growing demand for NSCLC profiling for selection of the most appropriate therapy, the acquisition of adequate tumor samples has become increasingly crucial, mostly in advanced NSCLC patients due to old age and/or comorbidities. Being a mini-invasive sampling technique, endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) represents a valuable alternative to traditional transthoracic or surgical sampling in these patients, and perfoming cell block (CB) could be crucial to maximize the potential biological information. The aim of this study is to describe a monoinstitutional interprofessional experience in handling EBUS-TBNA and CB in 464 patients.

METHODS

We retrospectively collected all the consecutive CBs obtained from EBUS TBNA performed between 2014 and 2021 on the lung lesions or mediastinal lymph nodes. All the CBs were handled in a standardized method.

RESULTS

A total of 95.5% (448/464 samples) of adequacy for site and 92.6% (430/464) of adequacy for diagnosis were observed. Moreover, in the adenocarcinoma histotype, ALK, ROS1 and tumor proportion score (TPS) PD-L1 assessment by IHC was possible in 96% (140/146) of cases, and molecular profile was obtained in 93.8% (137/146) of cases. In the squamous cell carcinoma histotype, TPS PD-L1 assessment was possible in 81% (13/16) of cases. All four CB results obtained from carcinoma NOS were adequate for ALK, ROS1 and PD-L1 assessment and molecular profiling. All 39 metastatic samples from extra-pulmonary primary were adequate for immunohistochemical characterization and molecular profiling. Finally, reporting of the tumor sample adequacy to the clinicians took a median time of about 30 h (range: 24-80 h).

CONCLUSION

Careful cytological smear management together with the handling and standardization of CB obtained from EBUS-TBNA could represent an effective method to increase the adequacy of the tumor specimen for both diagnosis and molecular profile.

Impact of KRAS Mutation Subtypes and Co-Occurring Mutations on Response and Outcome in Advanced NSCLC Patients following First-Line Treatment

(1) Background: The purpose was to systematically assess the impact of KRAS subtypes and co-mutations on responses of first-line treatment and outcomes by genetic classification in advanced KRAS mutant NSCLC. (2) Methods: Molecular pathology was confirmed with NGS; Kaplan−Meier analysis and Cox multivariate model were used to analyze the efficacy of first-line treatment and prognosis in KRAS subgroups. (3) Results: Advanced KRAS mutant NSCLC was confirmed among 183 patients, who received first-line therapy. The most common KRAS subtype and co-mutation were G12C (29.5%) and TP53 (59.6%). ICIs/CHE group prolonged PFS to 16.9 m, vs. (CHE)4.6 m vs. (CHE/BEV)7.0 m (p < 0.0001); mOS (ICIs/CHE)37.1 m vs. (CHE)19.8 m vs. [CHE/BEV] 20.7 m (p = 0.024). PFS benefited to different degrees after first-line ICI-based treatment in each genetic classification. KRAS G12D even benefited from OS (p = 0.045). CHE/BEV prolonged mPFS of KRAS/STK11 co-mutation (p = 0.043), but decreased mPFS in G12A subtype (p = 0.026). Multivariate analysis indicated that heavy smoking history (≥20 pack-years) (HR = 0.45, p = 0.039) predicts optimistic prognosis; PS score 1 (HR = 3.604, p = 0.002) and KRAS/SMAD4 co-mutation (HR = 4.293, p = 0.027) remained as independent predictors of shorter OS. (4) Conclusions: First-line treatment with ICI benefited KRAS-mutant-NSCLC patients and resulted in non-negative predictive value for any genetic classification. Bevacizumab should be cautiously chosen for patients with KRAS G12A subtype but is recommended for KRAS/STK11 patients. KRAS/SMAD4 is a new co-mutation genotype that displayed independent risk prognostic factors in patients with advanced KRAS-mutant NSCLC.

KRAS Mutations Impact Clinical Outcome in Metastatic Non-Small Cell Lung Cancer

There is an urgent need to identify new predictive biomarkers for treatment response to both platinum doublet chemotherapy (PT) and immune checkpoint blockade (ICB). Here, we evaluated whether treatment outcome could be affected by KRAS mutational status in patients with metastatic (Stage IV) non-small cell lung cancer (NSCLC). All consecutive patients molecularly assessed and diagnosed between 2016−2018 with Stage IV NSCLC in the region of West Sweden were included in this multi-center retrospective study. The primary study outcome was overall survival (OS). Out of 580 Stage IV NSCLC patients, 35.5% harbored an activating mutation in the KRAS gene (KRASMUT). Compared to KRAS wild-type (KRASWT), KRASMUT was a negative factor for OS (p = 0.014). On multivariate analysis, KRASMUT persisted as a negative factor for OS (HR 1.478, 95% CI 1.207−1.709, p < 0.001). When treated with first-line platinum doublet (n = 195), KRASMUT was a negative factor for survival (p = 0.018), with median OS of 9 months vs. KRASWT at 11 months. On multivariate analysis, KRASMUT persisted as a negative factor for OS (HR 1.564, 95% CI 1.124−2.177, p = 0.008). KRASMUT patients with high PD-L1 expression (PD-L1high) had better OS than PD-L1highKRASWT patients (p = 0.036). In response to first-line ICB, KRASMUT patients had a significantly (p = 0.006) better outcome than KRASWT patients, with a median OS of 23 vs. 6 months. On multivariable Cox analysis, KRASMUT status was an independent prognostic factor for better OS (HR 0.349, 95% CI 0.148−0.822, p = 0.016). kRAS mutations are associated with better response to treatment with immune checkpoint blockade and worse response to platinum doublet chemotherapy as well as shorter general OS in Stage IV NSCLC.

Analysis of Molecular Biomarkers in Resected Early-Stage Non-Small Cells Lung Cancer: A Narrative Review

Simple Summary

In the last few years, the treatment of advanced NSCLC has radically changed after the development of new drugs against specific molecular targets. Moreover, multiple tumour biopsies have become mandatory in order to better select the appropriate targeted therapy. Molecular analysis using NGS in the early stage of NSCLC is still relatively widespread. The recent clinical trials that use targeted therapies in neoadjuvant and adjuvant settings also require molecular characterisation for early-stage patients. Due to the widespread use of molecular analysis in patients with early-stage NSCLC, the prognostic role of molecular biomarkers needs to be fully understood. This paper aimed to review the most recent studies associating the molecular expressions of early-stage NSCLC with survival.

Abstract

Next-generation sequencing has become a cornerstone in clinical oncology practice and is recommended for the appropriate use of tailored therapies in NSCLC. While NGS has already been standardised in advanced-stage NSCLC, its use is still uncommon in the early stages. The recent approval of Osimertinib for resected EGFR-mutated NSCLC in an adjuvant setting has launched the hypothesis that other targeted therapies used in metastatic patients can also lead to improved early-stage outcomes of NSCLC. The impact of molecular biomarkers on the prognosis of patients undergoing radical surgery for NSCLC is still unclear. Notably, the heterogeneous populations included in the studies that analysed surgical patients could be the main reason for these results. In this review, we report the most important studies that analysed the impact of principal molecular biomarkers on the survival outcomes of patients who underwent radical surgery for NSCLC.

Syntenin-1-mediated small extracellular vesicles promotes cell growth, migration, and angiogenesis by increasing onco-miRNAs secretion in lung cancer cells

Small extracellular vesicles (sEVs) play a pivotal role in tumor progression by mediating intercellular communication in the tumor microenvironment (TME). Syntenin-1 induces malignant tumor progression in various types of human cancers, including human lung cancer and regulates biogenesis of sEVs. However, the function of syntenin-1-regulated sEVs and miRNAs in sEVs remains to be elucidated. In the present study, we aimed to demonstrate the role of oncogenic Ras/syntenin-1 axis in the release of sEVs and elucidate the function of syntenin-1-mediated miRNAs in sEVs in lung cancer progression. The results revealed that oncogenic Ras promoted the release of sEVs by inducing syntenin-1 expression; disruption of syntenin-1 expression impaired the release of sEVs as well as sEV-mediated cancer cell migration and angiogenesis. Moreover, we identified three miRNAs, namely miR-181a, miR-425-5p, and miR-494-3p, as onco-miRNAs loaded into syntenin-1-dependent sEVs. Remarkably, miR-494-3p was highly abundant in sEVs and its release was triggered by syntenin-1 expression and oncogenic Ras. Ectopic expression of the miR-494-3p mimic enhanced the migration and proliferation of lung cancer cells as well as tube formation in endothelial cells; however, the miR-494-3p inhibitor blocked sEV-mediated effects by targeting tyrosine-protein phosphatase nonreceptor type 12 (PTPN12), a tumor suppressor. sEVs promoted tumor growth and angiogenesis by downregulating PTPN12 expression; however, the miR-494-3p inhibitor significantly suppressed these effects in vivo, confirming that miR-494-3p acts as a major onco-miRNA loaded into lung cancer cell-derived sEVs. Eventually, the oncogenic Ras/syntenin-1 axis may induce cancer progression by increasing miR-494-3p loading into sEVs in lung cancer cells in the TME.

Molecular typing of lung adenocarcinoma with computed tomography and CT image-based radiomics: a narrative review of research progress and prospects

Objective

The purpose of this paper was to perform a narrative review of current research evidence on conventional computed tomography (CT) imaging features and CT image-based radiomic features for predicting gene mutations in lung adenocarcinoma and discuss how to translate the research findings to guide future practice.

Background

Lung cancer, especially lung adenocarcinoma, is the leading cause of cancer-related deaths. With advances in the diagnosis and treatment of lung adenocarcinoma with the emergence of molecular testing, the prediction of oncogenes and even drug resistance gene mutations have become key to individualized and precise clinical treatment in order to prolong survival and improve quality of life. The progress of imageological examination includes the development of CT and radiomics are promising quantitative methods for predicting different gene mutations in lung adenocarcinoma, especially common mutations, such as epidermal growth factor receptor (EGFR) mutation, anaplastic lymphoma kinase (ALK) mutation and Kirsten rat sarcoma viral oncogene (KRAS) mutation.

Methods

The PubMed electronic database was searched along with a set of terms specific to lung adenocarcinoma, radiomics (including texture analysis), CT, computed tomography, EGFR, ALK, KRAS, rearranging transfection (RET) rearrangement and c-ros oncogene 1 (ROS-1), v-raf murine sarcoma viral oncogene homolog B1 (BRAF), and human epidermal growth factor receptor 2 (HER2) mutations et al. This review has been reported in compliance with the Narrative Review checklist guidelines. From each full-text article, information was extracted regarding a set of terms above.

Conclusions

Research on the application of conventional CT features and CT image-based radiomic features for predicting the gene mutation status of lung adenocarcinoma is still in a preliminary stage. Noninvasively determination of mutation status in lung adenocarcinoma before targeted therapy with conventional CT features and CT image-based radiomic features remains both hopes and challenges. Before radiomics could be applied in clinical practice, more work needs to be done.

Retrospective Data Analysis of Patients With Metastatic Lung Adenocarcinoma With or Without KRAS-Mutation or TTF1-Expression

Introduction

Patients with lung adenocarcinoma not expressing TTF1 and those with a KRAS mutation have worse prognosis. However, available data are limited and sometimes contradictory. Therefore, this retrospective cohort analysis aimed to clarify whether there was a difference in overall survival and progression-free survival between these groups of patients.

Methods

In total, data derived from 181 patients with metastatic lung adenocarcinoma treated at the Martha-Maria Halle-Dölau Hospital from 2016 to 2019 were analyzed. Kaplan-Meier curves were generated, and associated values, such as median survival and its confidence intervals, were determined using the log-rank test.

Results

A benefit in overall survival (OS) (8.4 vs 5.8 months; HR, .8; 95% CI, .53-1.19; P = .267) was associated with positive TTF1 expression, but this was not statistically significant. The same trend was shown with the progressive free survival (PFS) (6.5 vs 4.6 months; HR, .76; 95% CI, .51-1.20; P = .162). In patients with a KRAS mutation, there was no difference in OS compared to those with a wildtype KRAS. The median survival was almost identical at 7.5 months (KRAS mutation, 95% CI, 3.32-11.74) and 7.0 months (KRAS wildtype, 95% CI, 3.59-10.41). Additionally, in PFS, there was no difference between the 2 groups (5.8 vs 6.3 months).

Conclusions

Our analysis did not show a worse prognosis in patients with a KRAS mutation or in those with missing TTF1 expression, which is most likely related to the new therapeutic options. As a result of the administration of immunotherapy in patients with a KRAS mutation and the change from a regimen containing pemetrexed to a regimen containing no pemetrexed, the corresponding patients no longer seem to have a worse prognosis.

Progress on Ras/MAPK Signaling Research and Targeting in Blood and Solid Cancers

Simple Summary

The Ras-Raf-MEK-ERK signaling pathway is responsible for regulating cell proliferation, differentiation, and survival. Overexpression and overactivation of members within the signaling cascade have been observed in many solid and blood cancers. Research often focuses on targeting the pathway to disrupt cancer initiation and progression. We aimed to provide an overview of the pathway’s physiologic role and regulation, interactions with other pathways involved in cancer development, and mutations that lead to malignancy. Several blood and solid cancers are analyzed to illustrate the impact of the pathway’s dysregulation, stemming from mutation or viral induction. Finally, we summarized different approaches to targeting the pathway and the associated novel treatments being researched or having recently achieved approval.

Abstract

The mitogen-activated protein kinase (MAPK) pathway, consisting of the Ras-Raf-MEK-ERK signaling cascade, regulates genes that control cellular development, differentiation, proliferation, and apoptosis. Within the cascade, multiple isoforms of Ras and Raf each display differences in functionality, efficiency, and, critically, oncogenic potential. According to the NCI, over 30% of all human cancers are driven by Ras genes. This dysfunctional signaling is implicated in a wide variety of leukemias and solid tumors, both with and without viral etiology. Due to the strong evidence of Ras-Raf involvement in tumorigenesis, many have attempted to target the cascade to treat these malignancies. Decades of unsuccessful experimentation had deemed Ras undruggable, but recently, the approval of Sotorasib as the first ever KRas inhibitor represents a monumental breakthrough. This advancement is not without novel challenges. As a G12C mutant-specific drug, it also represents the issue of drug target specificity within Ras pathway; not only do many drugs only affect single mutational profiles, with few pan-inhibitor exceptions, tumor genetic heterogeneity may give rise to drug-resistant profiles. Furthermore, significant challenges in targeting downstream Raf, especially the BRaf isoform, lie in the paradoxical activation of wild-type BRaf by BRaf mutant inhibitors. This literature review will delineate the mechanisms of Ras signaling in the MAPK pathway and its possible oncogenic mutations, illustrate how specific mutations affect the pathogenesis of specific cancers, and compare available and in-development treatments targeting the Ras pathway.

Current therapy of KRAS-mutant lung cancer

KRAS mutations are the most frequent gain-of-function alterations in patients with lung adenocarcinoma (LADC) in the Western world. Although they have been identified decades ago, prior efforts to target KRAS signaling with single-agent therapeutic approaches such as farnesyl transferase inhibitors, prenylation inhibition, impairment of KRAS downstream signaling, and synthetic lethality screens have been unsuccessful. Moreover, the role of KRAS oncogene in LADC is still not fully understood, and its prognostic and predictive impact with regards to the standard of care therapy remains controversial. Of note, KRAS-related studies that included general non-small cell lung cancer (NSCLC) population instead of LADC patients should be very carefully evaluated. Recently, however, comprehensive genomic profiling and wide-spectrum analysis of other co-occurring genetic alterations have identified unique therapeutic vulnerabilities. Novel targeted agents such as the covalent KRAS G12C inhibitors or the recently proposed combinatory approaches are some examples which may allow a tailored treatment for LADC patients harboring KRAS mutations. This review summarizes the current knowledge about the therapeutic approaches of KRAS-mutated LADC and provides an update on the most recent advances in KRAS-targeted anti-cancer strategies, with a focus on potential clinical implications.

Naproxen inhibits spontaneous lung adenocarcinoma formation in KrasG12V mice

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Naproxen inhibits the adenocarcinoma by 64% in Kras^G12V mice.

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Naproxen inhibits serum PGE₂/CXCR4 levels in Kras^G12V mice.

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Naproxen inhibits the progression of adenocarcinoma in Kras^G12V mice.

Lung cancer is the leading cause of cancer related deaths worldwide. The present study investigated the effects of naproxen (NSAID) on lung adenocarcinoma in spontaneous lung cancer mouse model. Six-week-old transgenic Kras^G12V mice (n = 20; male + female) were fed modified AIN-76A diets containing naproxen (0/400 ppm) for 30 wk and euthanized at 36 wk of age. Lungs were evaluated for tumor incidence, multiplicity, and histopathological stage (adenoma and adenocarcinoma). Lung tumors were noticeable as early as 12 wk of age exclusively in the Kras^G12V mice. By 36 wk age, 100% of Kras^G12V mice on control diet developed lung tumors, mostly adenocarcinomas. Kras^G12V mice fed control diet developed 19.8 ± 0.96 (Mean ± SEM) lung tumors (2.5 ± 0.3 adenoma, 17.3 ± 0.7 adenocarcinoma). Administration of naproxen (400 ppm) inhibited lung tumor multiplicity by ∼52% (9.4 ± 0.85; P < 0001) and adenocarcinoma by ∼64% (6.1 ± 0.6; P < 0001), compared with control-diet-fed mice. However, no significant difference was observed in the number of adenomas in either diet, suggesting that naproxen was more effective in inhibiting tumor progression to adenocarcinoma. Biomarker analysis showed significantly reduced inflammation (COX-2, IL-10), reduced tumor cell proliferation (PCNA, cyclin D1), and increased apoptosis (p21, caspase-3) in the lung tumors exposed to naproxen. Decreased serum levels of PGE₂ and CXCR4 were observed in naproxen diet fed Kras^G12V mice. Gene expression analysis of tumors revealed a significant increase in cytokine modulated genes (H2-Aa, H2-Ab1, Clu), which known to further modulate the cytokine signaling pathways. Overall, the results suggest a chemopreventive role of naproxen in inhibiting spontaneous lung adenocarcinoma formation in Kras^G12V mice.

Suppression of m6A mRNA modification by DNA hypermethylated ALKBH5 aggravates the oncological behavior of KRAS mutation/LKB1 loss lung cancer

Oncogenic KRAS mutations combined with the loss of the LKB1 tumor-suppressor gene (KL) are strongly associated with aggressive forms of lung cancer. N6-methyladenosine (m6A) in mRNA is a crucial epigenetic modification that controls cancer self-renewal and progression. However, the regulation and role of m6A modification in this cancer are unclear. We found that decreased m6A levels correlated with the disease progression and poor survival for KL patients. The correlation was mediated by a special increase in ALKBH5 (AlkB family member 5) levels, an m6A demethylase. ALKBH5 gain- or loss-of function could effectively reverse LKB1 regulated cell proliferation, colony formation, and migration of KRAS-mutated lung cancer cells. Mechanistically, LKB1 loss upregulated ALKBH5 expression by DNA hypermethylation of the CTCF-binding motif on the ALKBH5 promoter, which inhibited CTCF binding but enhanced histone modifications, including H3K4me3, H3K9ac, and H3K27ac. This effect could successfully be rescued by LKB1 expression. ALKBH5 demethylation of m6A stabilized oncogenic drivers, such as SOX2, SMAD7, and MYC, through a pathway dependent on YTHDF2, an m6A reader protein. The above findings were confirmed in clinical KRAS-mutated lung cancer patients. We conclude that loss of LKB1 promotes ALKBH5 transcription by a DNA methylation mechanism, reduces m6A modification, and increases the stability of m6A target oncogenes, thus contributing to aggressive phenotypes of KRAS-mutated lung cancer.

The improbable targeted therapy: KRAS as an emerging target in non-small cell lung cancer (NSCLC)

KRAS is a frequent oncogenic driver in solid tumors, including non-small cell lung cancer (NSCLC). It was previously thought to be an "undruggable" target due to the lack of deep binding pockets for specific small-molecule inhibitors. A better understanding of the mechanisms that drive KRAS transformation, improved KRAS-targeted drugs, and immunological approaches that aim at yielding immune responses against KRAS neoantigens have sparked a race for approved therapies. Few treatments are available for KRAS mutant NSCLC patients, and several approaches are being tested in clinicals trials to fill this void. Here, we review promising therapeutics tested for KRAS mutant NSCLC.

[Progress in Survival Prognosis of Segmentectomy for Early-stage Non-small Cell Lung Cancer]

Surgery is currently the most appropriate treatment for early-stage non-small cell lung cancer (NSCLC). Increasing unilateral or bilateral multiple primary lung cancer being found, segmentectomy has attracted wide attention for its unique advantages in the treatment for such tumors. Ground glass opacity dominant early-stage NSCLC is associated with a good prognosis and can be cured by segmentectomy, however, the treatment of solid-dominant NSCLC remains controversial owing to the invasive nature. With the in-depth study on the lymph node metastasis pathway, radiological characteristics and molecular biology of NSCLC, a large part of solid nodules with certain characteristics can also be cured by segmentectomy. This paper reviews the research status and progress about the indication of segmentectomy.
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Genomic characteristics in Chinese non-small cell lung cancer patients and its value in prediction of postoperative prognosis

Background

The genomic profile of non-small cell lung cancer (NSCLC) in Asians is distinct from that of Caucasians, but comprehensive genetic profiling reports have been limited for Asian patients. We aimed to elucidate genomic characteristics of Chinese NSCLC patients and develop potential model including genomic characteristics to predict postoperative prognosis.

Methods

Resected tumor samples from 511 patients with stage I–IV lung cancer were subjected to targeted sequencing using a panel of 295 cancer-related genes. Based on the molecular profiles and clinical features, we established nomogram models with predictors consisting of integrated clinical and genomic characteristics to provide post-operative risk stratification.

Results

Compared to the TCGA population (mainly Caucasians), there was a significantly higher frequency of EGFR (53.7% vs. 14.4%) and NOTCH3 (8.4% vs. 1.3%) mutations and less mutated KRAS (11.0% vs. 32.6%), KEAP1 (4.4% vs. 17.4%) and LRP1B (16.3% vs. 29.6%) in Chinese lung adenocarcinomas (LUAD). Distinct patterns of mutually exclusive and co-occurring mutations were identified between LUAD and lung squamous cell carcinoma (LUSC), indicating the unique histology-specific tumorigenesis mechanism of each subtype. We observed alterations in pathways correlated with clinical characteristics. Additionally, we constructed nomogram model with predictors consisting of clinical and genomic characteristics, which were more accurate than models with clinical characteristics or TNM staging only both in stage I–IIIA patients and T1-2N0M0 sub-cohort.

Conclusions

This study revealed Chinese NSCLC patients have unique genomic profile. Furthermore, the nomogram model combining clinical features with genomic characteristics could improve risk stratification in early-stage NSCLC.

KRAS mutation as a prognostic factor and predictive factor in advanced/metastatic non-small cell lung cancer: A systematic literature review and meta-analysis

KRAS (Kirsten Rat Sarcoma) is the most common oncogenic mutation detected in patients with non-small cell lung cancer (NSCLC). However, the role of KRAS as either a prognostic factor or predictive factor (modifier of treatment effects) in NSCLC is not well established at this time. This systematic literature review (SLR) and meta-analysis synthesized the available evidence regarding the role of KRAS mutation as a predictive factor and/or prognostic factor of survival and response outcomes in patients with advanced/metastatic (stage IIIB-IV) NSCLC. Relevant clinical trials and observational studies were identified by searching MEDLINE, Embase and Cochrane Register of Controlled Trials. Meta-analyses were performed using data extracted from multivariable and univariable analyses from clinical studies to assess the empirical evidence of KRAS mutation status as a prognostic or/and predicitive factor. 43 selected studies were identified by the SLR and included in this meta-analysis. Pairwise meta-analyses of hazard ratios (HRs) reported in randomized controlled trials (RCTs) did not demonstrate a significant prognostic effect of mutant KRAS on overall survival (OS) (HR=1.10; 95% CI [0.88, 1.38]) or progression free survival (PFS) (HR=1.03; 95% CI [0.80, 1.33]). However, when conducting meta-analyses on HRs reported in observational studies, a statistically significant negative prognostic effect of mutant KRAS was observed (OS HR=1.71; 95% CI [1.07, 2.84]; PFS HR=1.18; 95% CI [1.02, 1.36]). Meta-analyses of objective response rate (ORR) in RCTs demonstrated a negative prognostic effect of mutant KRAS (RR=0.38; 95% CI [0.16, 0.63]). Limited data were available to evaluate the role of KRAS mutation as a predictive factor. In conclusion, this research offers evidence that KRAS mutation may be a negative prognostic factor for survival and response outcomes in patients with advanced/metastatic NSCLC, but further research is needed to address conflicting results on the importance of KRAS mutations as a predictive factor.

Real world outcomes in KRAS G12C mutation positive non-small cell lung cancer

BACKGROUND

KRAS mutations are found in 20-30 % of non-small cell lung cancers (NSCLC) and were traditionally considered undruggable. KRAS^G12C mutation confers sensitivity to KRAS^G12C covalent inhibitors, however its prognostic impact remains unclear. This study assesses the frequency, clinical features, prevalence of brain metastases and outcomes in KRAS^G12C NSCLC in a real-world setting.

METHODS

Patients enrolled in the prospective Thoracic Malignancies Cohort (TMC) between July 2012 to October 2019 with recurrent/metastatic non-squamous NSCLC, available KRAS results, and without EGFR/ALK/ROS1 gene aberrations, were selected. Data was extracted from TMC and patient records. Clinicopathologic features, treatment and overall survival (OS) was compared for KRAS wildtype (KRAS^WT) and KRAS mutated (KRAS^mut); and KRAS^G12C and other (KRAS^other) mutations.

RESULTS

Of 1386 NSCLC patients, 1040 were excluded: non-metastatic/recurrent (526); unknown KRAS status (356); ALK/EGFR/ROS1 positive (154); duplicate (4). Of 346 patients analysed, 144 (42 %) were KRAS^mut, of whom 65 (45 %) were KRAS^G12C. All patients with KRAS^G12C were active or ex-smokers, compared to 92 % of KRAS^other and 83 % of KRAS^WT. The prevalence of brain metastases during follow-up was similar between KRAS^mut and KRAS^WT (33 % vs 40 %, p = 0.17), and KRAS^G12C and KRAS^other (40 % vs 41 %, p = 0.74). The proportion of patients receiving one or multiple lines of systemic therapy was comparable. OS was similar between KRAS^mut and KRAS^WT (p = 0.54), and KRAS^G12C and KRAS^other (p = 0.39).

CONCLUSION

Patients with KRAS^mut and KRAS^WT, and KRAS^G12C and KRAS^other NSCLC have comparable clinical features, treatment and survival. While not prognostic, KRAS^G12C may be an important predictive biomarker as promising KRAS^G12C covalent inhibitors continue to be developed.

Bronchoscopic tissue yield for advanced molecular testing: are we getting enough?

The treatment of advanced lung cancer has become increasingly personalized over the past decade as a result of the improved understanding of tumor molecular biology and anti-tumor immunity. An adequate tumor sample is central to targetable mutation analysis, and immunologic profiling. The majority of lung cancer patients currently present at an advanced disease stage, so that diagnosis and staging are largely based on small biopsy and cytology specimens. Flexible bronchoscopy techniques play a prominent role in the acquisition of these diagnostic specimens. This narrative review summarizes the available evidence with regards to the role of various conventional and advanced flexible bronchoscopy techniques in acquiring sufficient tissue for mutation analysis and programmed death-ligand 1 (PD-L1) testing.

Prognostic value and therapeutic implications of expanded molecular testing for resected early stage lung adenocarcinoma

OBJECTIVES

This study aimed to evaluate the prognostic and potential therapeutic value of expanded molecular testing of resected early-stage lung ACA.

METHODS

We analyzed 324 patients who underwent lobectomy and lymphadenectomy for clinical Stage I&II lung ACA between 2011-2017. Molecular testing was routinely performed, first by PCR-based Sanger sequencing and FISH and then expanded to a 20 and then 50-gene next generation sequencing (NGS) panel. The frequency of mutations by testing method and their association with disease-free (DFS) and overall survival (OS) were tested.

RESULTS

A total of 241 patients (74.4%) had at least one somatic mutation detected, with KRAS exon 2 (38.1%) and EGFR (17.9%) being the most common. TP53 was the most frequent co-existing mutation. Detection of at least one mutation increased from 49% with selective PCR/FISH testing to 82% with limited NGS/FISH, and 91% with extended NGS/FISH (p < 0.001). The rate of actionable mutations increased from 18% to 32% and 45% with expansion of molecular testing, respectively (p = 0.001). Using NGS, an additional 10 cases with EGFR mutations, and other rare mutations were found, including BRAF (5.9%), MET (5.6%), ERBB2 (4.1%), PIK3CA (2.3%), and DDR2 (2.1%). The expansion of FISH testing resulted in one additional detection of ROS1 and RET (1%) rearrangement. KRAS mutation was associated with worse DFS (HR 1.87; 95%CI 1.14-3.06) and OS (HR 2.09; 95%CI 1.11-3.92). BRAF mutation detected in NGS tested patients was also associated with decreased DFS (HR3.80; 95%CI 1.46-9.89) and OS (HR 7.37; 95%CI 2.36-22.99) on multivariate analysis.

CONCLUSION

The expansion of molecular testing has resulted in a substantial increase in the detection of potentially therapeutically significant mutations in resected early-stage ACA. KRAS and BRAF mutation status by NGS was prognostic for relapse and survival. These data emphasize opportunities for clinical trials in a growing number surgical ACA patients with available targeted therapies.

Targeting non-small cell lung cancer: driver mutation beyond epidermal growth factor mutation and anaplastic lymphoma kinase fusion

The identification of driver mutations in epidermal growth factor receptor, anaplastic lymphoma kinase, the BRAF and ROS1 genes and subsequent successful clinical development of kinase inhibitors not only significantly improves clinical outcomes but also facilitates the discovery of other novel driver mutations in non-small cell lung cancer. These driver mutations can be categorized into mutations in or near the kinase domain, gene amplification or fusion. In this review, BRAF V600E, EGFR and HER-2 exon 20 mutation, FGFR1-4, K-RAS, MET, neuregulin-1, NRTK, PI3K/AKT/mTOR, RET and ROS1 gene aberration and their therapeutics will be discussed.

[Advances in Lymph Node Metastasis and Lymph Node Dissection in Early Non-small Cell Lung Cancer]

肺癌是目前我国发病率和死亡率均居首位的恶性肿瘤，其中以非小细胞肺癌为主要病理类型。淋巴结转移是非小细胞肺癌最常见和最主要的转移途径，也是影响肺癌分期和预后最重要的因素。由于目前通过现有手段术前很难准确判断早期非小细胞肺癌患者的淋巴结受累情况。因此，在早期非小细胞肺癌中，尤其是在临床Ⅰ期非小细胞肺癌患者中，淋巴结清扫方式一直存在很大争议。本文就非小细胞肺癌淋巴结转移的规律及清扫方式进行综述。

Invasive mucinous adenocarcinoma of the lung

Invasive mucinous adenocarcinoma (IMA) is a unique histological subtype of adenocarcinoma. Due to its low incidence rates, survival data for IMA is scarce and often contradictory. The clinical manifestations of IMA are not precise as compared to other adenocarcinomas, with some patients having bronchial mucus overflow. Difference in immunohistochemical expression levels is present in IMA and invasive non-mucinous adenocarcinomas (INMA). Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations are more frequent in IMAs, while epidermal growth factor receptor (EGFR) mutations are relatively rare. This makes it distinct from the other more common adenocarcinomas. Neuregulin 1 (NRG1) gene fusions are considered important therapeutic targets for IMA, suggesting that Afatinib may be an effective drug to treat IMA. However, IMA prognosis remains controversial.

Economic Impact of Next-Generation Sequencing Versus Single-Gene Testing to Detect Genomic Alterations in Metastatic Non–Small-Cell Lung Cancer Using a Decision Analytic Model

PURPOSE

The aim of the current study was to assess the economic impact of using next-generation sequencing (NGS) versus single-gene testing strategies among patients with metastatic non–small-cell lung cancer (mNSCLC) from the perspective of the Centers for Medicare & Medicaid Services (CMS) and US commercial payers.

METHODS

A decision analytic model considered patients who were newly diagnosed with mNSCLC who received programmed death ligand 1 and genomic alteration tests— EGFR, ALK, ROS1, BRAF, MET, HER2, RET, and NTRK1—using upfront NGS (all alterations tested simultaneously plus KRAS), sequential testing (sequence of single-gene tests), exclusionary testing ( KRAS plus sequential testing), and hotspot panels ( EGFR, ALK, ROS1, and BRAF tested simultaneously plus single-gene tests or NGS for MET, HER2, RET, and NTRK1). Model outcomes for each strategy were time-to-test results, the proportion of patients identified harboring alterations with or without US Food and Drug Administration–approved therapies, and total testing costs. A budget impact analysis assessed the economic effects of increasing the proportion of NGS-tested patients.

RESULTS

In a hypothetical 1,000,000-member health plan, 2,066 Medicare-insured patients and 156 commercially insured patients were estimated to have mNSCLC and to be eligible for testing. Time-to-test results were 2.0 weeks for NGS and the hotspot panel, faster than exclusionary and sequential testing by 2.7 and 2.8 weeks, respectively. NGS was associated with cost savings for both CMS ($1,393,678; $1,530,869; and $2,140,795 less than exclusionary, sequential testing, and hotspot panels, respectively) and commercial payers ($3,809; $127,402; and $250,842 less than exclusionary, sequential testing, and hotspot panels, respectively). Increasing the proportion of NGS-tested patients translated into substantial cost savings for both CMS and commercial payers.

CONCLUSION

Use of upfront NGS testing in patients with mNSCLC was associated with substantial cost savings and shorter time-to-test results for both CMS and commercial payers.

Dual-energy spectral CT characteristics in surgically resected lung adenocarcinoma: comparison between Kirsten rat sarcoma viral oncogene mutations and epidermal growth factor receptor mutations

BACKGROUND

Kirsten rat sarcoma viral oncogene homolog (KRAS) and epidermal growth factor receptor (EGFR) are the two most frequent and well-known oncogene of lung adenocarcinoma. The purpose of this study is to compare the characteristics measured with dual-energy spectral computed tomography (DESCT) in lung adenocarcinoma patients who have KRAS and EGFR gene mutations.

METHODS

Patients with surgically resected lung adenocarcinoma (n = 72) were enrolled, including 12 patients with KRAS mutations and 60 patients with EGFR mutations. DESCT quantitative parameters, including the CT number at 70 keV, the slopes of the spectral attenuation curves (slope λ HU), normalized iodine concentration (NIC), normalized water concentration (NWC), and effective atomic number (effective Z), were analyzed. A multiple logistic regression model was applied to discriminate clinical and DESCT characteristics between the types of mutations.

RESULTS

The KRAS mutation was more common in people who smoked than the EGFR mutation. Nodule type differed significantly between the KRAS and EGFR groups (P = 0.035), and all KRAS mutation adenocarcinomas were solid nodules. Most DESCT quantitative parameters differed significantly between solid nodules and subsolid nodules. CT number at 70 keV, slope λ HU, NIC, and effective Z differed significantly between the KRAS and EGFR groups (P = 0.006, 0.017, 0.013 and 0.010) with solid lung adenocarcinoma. Multivariate logistic analysis of DESCT and clinical features indicated that besides smoking history, the CT value at 70 keV (OR = 0.938, P = 0.009) was significant independent factor that could be used to differentiate KRAS and EGFR mutations in solid lung adenocarcinoma.

CONCLUSIONS

DESCT would be a potential tool to differentiate lung adenocarcinoma patients with a KRAS mutation from those with an EGFR mutation.

Phase Ib/II study of hydroxychloroquine in combination with chemotherapy in patients with metastatic non-small cell lung cancer (NSCLC)

OBJECTIVES

Activation of cell survival pathways such as autophagy represents a potential resistance mechanism to chemotherapy in NSCLC. Preclinical studies report that autophagy inhibition suppresses lung tumor development and progression. We report the safety and efficacy for adding autophagy inhibitor, hydroxychloroquine, to chemotherapy in a phase Ib/II single-arm study in patients with metastatic NSCLC.

PATIENTS AND METHODS

We treated patients with untreated metastatic NSCLC with carboplatin, paclitaxel (and bevacizumab if criteria met) and hydroxychloroquine 200 mg BID. Patients continued on hydroxychloroquine (+/- bevacizumab) maintenance after 4-6 cycles of therapy.

RESULTS

We enrolled 40 patients, 8 on phase Ib and 32 on phase II. Forty-three percent were female; 50% with squamous histology. Median age was 62 years (range, 43-73). Thirteen patients developed ≥grade 3 treatment-related adverse event. Common adverse events (all grades) were neutropenia (35%), neuropathy (32.5%), and anemia (32.5%). The objective response rate (ORR) was 33% in the 30 patients (phase II) evaluable for response. Additionally, 20% of the patients demonstrated stable disease (clinical benefit rate of 53%). The median PFS was 3.3 months (95% CI 2.1-6.8 months). In 9 patients with KRAS positive tumors, ORR was 44% and median PFS was higher than expected at 6.4 months (95% CI 1.8-15.6).

CONCLUSIONS

Addition of hydroxychloroquine is safe and tolerable with a modest improvement in clinical responses compared to prior studies. Autophagy inhibition may overcome chemotherapy resistance in advanced NSCLC and further study in a more molecularly selected population such as KRAS-positive tumors is warranted.

Regulation of RhoB Gene Expression during Tumorigenesis and Aging Process and Its Potential Applications in These Processes

RhoB, a member of the Ras homolog gene family and GTPase, regulates intracellular signaling pathways by interfacing with epidermal growth factor receptor (EGFR), Ras, and phosphatidylinositol 3-kinase (PI3K)/Akt to modulate responses in cellular structure and function. Notably, the EGFR, Ras, and PI3K/Akt pathways can lead to downregulation of RhoB, while simultaneously being associated with an increased propensity for tumorigenesis. Functionally, RhoB, part of the Rho GTPase family, regulates intracellular signaling pathways by interfacing with EGFR, RAS, and PI3K/Akt/mammalian target of rapamycin (mTOR), and MYC pathways to modulate responses in cellular structure and function. Notably, the EGFR, Ras, and PI3K/Akt pathways can lead to downregulation of RhoB, while simultaneously being associated with an increased propensity for tumorigenesis. RHOB expression has a complex regulatory backdrop consisting of multiple histone deacetyltransferase (HDACs 1 and 6) and microRNA (miR-19a, -21, and -223)-mediated mechanisms of modifying expression. The interwoven nature of RhoB’s regulatory impact and cellular roles in regulating intracellular vesicle trafficking, cell motion, and the cell cycle lays the foundation for analyzing the link between loss of RhoB and tumorigenesis within the context of age-related decline in RhoB. RhoB appears to play a tissue-specific role in tumorigenesis, as such, uncovering and appreciating the potential for restoration of RHOB expression as a mechanism for cancer prevention or therapeutics serves as a practical application. An in-depth assessment of RhoB will serve as a springboard for investigating and characterizing this key component of numerous intracellular messaging and regulatory pathways that may hold the connection between aging and tumorigenesis.

When to Consider Immune Checkpoint Inhibitors in Oncogene-Driven Non-Small Cell Lung Cancer?

OPINION STATEMENT

Targeted therapies and more recently immune checkpoint inhibitors (ICI) have transformed the treatment landscape of advanced NSCLC. Clinical trials investigating immune checkpoint inhibitors (ICI) have usually excluded patients with oncogenic drivers, so that the outcome of these agents in this population is poorly known. In patients with oncogenic addiction, targeted therapy remains clearly the best option, and the place of immunotherapy in this population has not been clearly defined yet.Based on available data, we suggest that (i) immunotherapy single agent should be proposed only after exhaustion of more validated treatments, (ii) combinations of immunotherapy with targeted therapies are of interest provided that we can manage toxicity and find the best sequence, (iii) a combination of immunotherapy with chemotherapy may be appealing in patients pretreated with targeted agents. The best way to opt in for the best strategy will depend upon the identification of adequate biomarkers. New basic and clinical research is awaited in this field.

Toward automatic prediction of EGFR mutation status in pulmonary adenocarcinoma with 3D deep learning

To develop a deep learning system based on 3D convolutional neural networks (CNNs), and to automatically predict EGFR‐mutant pulmonary adenocarcinoma in CT images. A dataset of 579 nodules with EGFR mutation status labels of mutant (Mut) or wild‐type (WT) was retrospectively analyzed. A deep learning system, namely 3D DenseNets, was developed to process 3D patches of nodules from CT data, and learn strong representations with supervised end‐to‐end training. The 3D DenseNets were trained with a training subset of 348 nodules and tuned with a development subset of 116 nodules. A strong data augmentation technique, mixup, was used for better generalization. We evaluated our model on a holdout subset of 115 nodules. An independent public dataset of 37 nodules from the cancer imaging archive (TCIA) was also used to test the generalization of our method. Conventional radiomics analysis was also performed for comparison. Our method achieved promising performance on predicting EGFR mutation status, with AUCs of 75.8% and 75.0% for our holdout test set and public test set, respectively. Moreover, strong relations were found between deep learning feature and conventional radiomics, while deep learning worked through an enhanced radiomics manner, that is, deep learned radiomics (DLR), in terms of robustness, compactness and expressiveness. The proposed deep learning system predicts EGFR‐mutant of lung adenocarcinomas in CT images noninvasively and automatically, indicating its potential to help clinical decision‐making by identifying eligible patients of pulmonary adenocarcinoma for EGFR‐targeted therapy.

Small Molecule KRAS Agonist for Mutant KRAS Cancer Therapy

Background

Lung cancer patients with KRAS mutation(s) have a poor prognosis due in part to the development of resistance to currently available therapeutic interventions. Development of a new class of anticancer agents that directly targets KRAS may provide a more attractive option for the treatment of KRAS-mutant lung cancer.

Results

Here we identified a small molecule KRAS agonist, KRA-533, that binds the GTP/GDP-binding pocket of KRAS. In vitro GDP/GTP exchange assay reveals that KRA-533 activates KRAS by preventing the cleavage of GTP into GDP, leading to the accumulation of GTP-KRAS, an active form of KRAS. Treatment of human lung cancer cells with KRA-533 resulted in increased KRAS activity and suppression of cell growth. Lung cancer cell lines with KRAS mutation were relatively more sensitive to KRA-533 than cell lines without KRAS mutation. Mutating one of the hydrogen-bonds among the KRA-533 binding amino acids in KRAS (mutant K117A) resulted in failure of KRAS to bind KRA-533. KRA-533 had no effect on the activity of K117A mutant KRAS, suggesting that KRA-533 binding to K117 is required for KRA-533 to enhance KRAS activity. Intriguingly, KRA-533-mediated KRAS activation not only promoted apoptosis but also autophagic cell death. In mutant KRAS lung cancer xenografts and genetically engineered mutant KRAS-driven lung cancer models, KRA-533 suppressed malignant growth without significant toxicity to normal tissues.

Conclusions

The development of this KRAS agonist as a new class of anticancer drug offers a potentially effective strategy for the treatment of lung cancer with KRAS mutation and/or mutant KRAS-driven lung cancer.

Electronic supplementary material

The online version of this article (10.1186/s12943-019-1012-4) contains supplementary material, which is available to authorized users.

Dual inhibition of MEK and p38 impairs tumor growth in KRAS-mutated non-small cell lung cancer

Despite the high frequency of KRAS mutations in non-small cell lung cancer (NSCLC), therapeutic modalities targeting KRAS-mutated NSCLC have not been established. Based on our previous findings that mutant KRAS knockdown sensitized NSCLC cells to a p38 inhibitor, the growth-inhibitory effect of dual MEK and p38 inhibition on tumor growth in NSCLC cells harboring KRAS mutations was investigated. In KRAS-mutated NSCLC cells, the MEK inhibitor, selumetinib, inhibited cell growth in a dose-dependent manner, and its growth-inhibitory effect was enhanced by combined treatment with the p38 inhibitor LY2228820. Similarly, another pair of MEK and p38 inhibitors also exhibited antitumor activity. Small interfering RNAs (siRNAs) against MAPK14, which encodes p38α MAPK, enhanced the growth-inhibitory effect of the MEK inhibitors in NSCLC cells with KRAS mutations. Notably, MEK inhibitors reduced p38 expression levels but increased p38 phosphorylation levels, resulting in sensitization to p38 inhibitors in KRAS-mutated NSCLC cells. These results provide evidence that dual MEK and p38 inhibition could be a potent therapeutic strategy against oncogenic KRAS-driven NSCLC.

Prognostic value of KRAS/TP53/PIK3CA in non-small cell lung cancer

The present study explored the association between KRAS proto-oncogene GTPase (KRAS), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α (PIK3CA) and tumor protein p53 (TP53) mutations, and the clinical features and survival prognosis in 50 patients with non-small cell lung cancer (NSCLC). The most common concurrent single gene mutation was TP53, followed by KRAS and PIK3CA. Co-existing mutations were found in 17 patients. KRAS, PIK3CA and TP53 mutations were associated with carbohydrate antigen 19-9 expression, invasive growth, vacuolar signs and margin lobulation on chest CT. The incidence of distant metastasis (bone and adrenal) with KRAS and TP53 mutations was greater than that of local metastasis (pleura). Patients with the wild-type genes experienced longer progression-free survival (PFS) times than those with KRAS, TP53, KRAS/TP53 or PIK3CA/TP53 mutations. Patients with KRAS/TP53 or PIK3CA/TP53 mutations experienced shorter PFS times than those with a single KRAS or TP53 mutation. KRAS, PIK3CA and TP53 mutations were associated with distant metastases and a poor prognosis. Patients with NSCLC should receive routine KRAS, PIK3CA and TP53 gene sequencing to determine mutations for the analysis of clinical characteristics and prognosis.

First-line Chemotherapy Responsiveness and Patterns of Metastatic Spread Identify Clinical Syndromes Present Within Advanced KRAS Mutant Non-Small-cell Lung Cancer With Different Prognostic Significance

BACKGROUND

Unsuccessful KRAS-specific treatment approaches in non-small-cell lung cancer (NSCLC) might reflect underlying disease heterogeneity. We sought to define clinical "syndromes" within advanced KRAS mutant NSCLC to improve future clinical trials and create a clinical framework for future molecular development.

PATIENTS AND METHODS

To test a series of a priori hypotheses regarding KRAS-mutant NSCLC clinical syndromes, we conducted a multi-institutional retrospective medical record review. Survival probabilities were estimated using the Kaplan-Meier model. Between-group differences were assessed using the log-rank test. Multivariate Cox regression analyses and Wilcoxon rank sum testing were used to assess progression-free survival and overall survival (OS) differences.

RESULTS

Among 218 patients with advanced KRAS-mutant NSCLC, OS and progression-free survival with first-line chemotherapy did not differ by intrathoracic versus extrathoracic spread, smoking intensity, or the specific KRAS mutation. Metastatic disease at diagnosis resulted in significantly worse OS than recurrent, unresectable disease (median OS, 14.6 vs. 40.9 months; P = .001). Among the patients with metastatic disease at diagnosis, nonscalp, soft tissue metastases (syndrome X; 6% of cases; 95% confidence interval [CI], 2.5%-10.1%) signified a poor prognosis (median OS, 7.5 vs. 15.9 months for the controls; P = .021). The response to first-line chemotherapy (syndrome Y; 41% of cases; 95% CI, 32.3%-50.6%) signified a good prognosis (median OS, 26.7 vs. 11.9 months; P = .002). The overlap between these 2 syndromes was minimal (2 of 111). Multivariate analysis confirmed these observations. The hazard ratio for death for syndromes X and Y was 2.64 (95% CI, 1.13-6.14) and 0.45 (95% CI, 0.28-0.76), respectively.

CONCLUSION

Chemotherapy-responsive disease and nonscalp, soft tissue spread might represent distinct clinical syndromes within KRAS-mutant NSCLC. The molecular biology underlying this heterogeneity warrants future studies.

Metformin Enhances Cisplatin-Induced Apoptosis and Prevents Resistance to Cisplatin in Co-mutated KRAS/LKB1 NSCLC

INTRODUCTION

We hypothesized that activating KRAS mutations and inactivation of the liver kinase B1 (LKB1) oncosuppressor can cooperate to sustain NSCLC aggressiveness. We also hypothesized that the growth advantage of KRAS/LKB1 co-mutated tumors could be balanced by higher sensitivity to metabolic stress conditions, such as metformin treatment, thus revealing new strategies to target this aggressive NSCLC subtype.

METHODS

We retrospectively determined the frequency and prognostic value of KRAS/LKB1 co-mutations in tissue specimens from NSCLC patients enrolled in the TAILOR trial. We generated stable LKB1 knockdown and LKB1-overexpressing isogenic H1299 and A549 cell variants, respectively, to test the in vitro efficacy of metformin. We also investigated the effect of metformin on cisplatin-resistant CD133⁺ cells in NSCLC patient-derived xenografts.

RESULTS

We found a trend towards worse overall survival in patients with KRAS/LKB1 co-mutated tumors as compared to KRAS-mutated ones (hazard ratio: 2.02, 95% confidence interval: 0.94-4.35, p = 0.072). In preclinical experiments, metformin produced pro-apoptotic effects and enhanced cisplatin anticancer activity specifically in KRAS/LKB1 co-mutated patient-derived xenografts. Moreover, metformin prevented the development of acquired tumor resistance to 5 consecutive cycles of cisplatin treatment (75% response rate with metformin-cisplatin as compared to 0% response rate with cisplatin), while reducing CD133⁺ cells.

CONCLUSIONS

LKB1 mutations, especially when combined with KRAS mutations, may define a specific and more aggressive NSCLC subtype. Metformin synergizes with cisplatin against KRAS/LKB1 co-mutated tumors, and may prevent or delay the onset of resistance to cisplatin by targeting CD133⁺ cancer stem cells. This study lays the foundations for combining metformin with standard platinum-based chemotherapy in the treatment of KRAS/LKB1 co-mutated NSCLC.